@media screen and (max-width: 767px) {
    .gmap {
        position: relative;
        height: 0;
        overflow: hidden;
        width: 100%;
        padding-bottom: 75%;
    }
}

@media screen and (min-width: 768px) {
    .gmap {
        position: relative;
        height: 0;
        overflow: hidden;
        width: 100%;
        padding-bottom: 75%;
    }
}

@media screen and (min-width: 992px) {
    .gmap {
        position: relative;
        height: 0;
        overflow: hidden;
        width: 640px;
        padding-bottom: 480px;
    }
}

.gmap iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}